1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to displaying images, and more particularly, to controlling an external device through registration of a control ownership.
2. Description of the Related Art
Recently, various kinds of digital devices have appeared, and Institute of Electrical and Electronics Engineers (IEEE) 1394 is being looked to as a digital interface for constructing a network among such devices. In particular, the IEEE 1394 has become a matter of greater concern as it is recognized as the sole standard for transmitting High Definition (HD) streams in a digital television field.
The IEEE 1394 is the standard of a serial interface standardized by the Institute of Electrical and Electronics Engineers. Three kinds of data transfer rates, e.g., 100 MB, 200 MB and 400 MB per second, have been prescribed. The IEEE 1394 supports a hot plug-in function that enables slave devices to be directly connected to a host device which is in operation, and in this case, sixty-three slave devices can be connected to the host device at maximum. Data transmission can be classified into two types: isochronous transmission and asynchronous transmission. The isochronous transmission is a real-time transmission, and thus it is suitable to an interface for transmitting multimedia information that requires simultaneity such as a moving image or voice. The asynchronous transmission divides data and transmits the divided data, and thus it can be used to transfer data between a personal computer and a peripheral device, such as a printer.
An IEEE 1394 interface connects a video camera, an audio appliance, a television receiver, a video cassette recorder (VCR), a set-top box, an audio/video hard disk drive (AVHDD), a DVHS, an MPEG camcorder, a personal computer, and a digital television receiver in a group, and all the connected devices can perform data transmission/reception with one another.
The digital television receiver can read data stored in the AVHDD, and play and display the read data on its screen by transmitting a playback command to the AVHDD through the IEEE 1394 interface.
On the other hand, the number of external devices that can be connected to a storage device such as the AVHDD is limited. Accordingly, an output signal of an external device that selects the AVHDD is under the control of the external device that has finally transmitted the playback command to the AVHDD.
For example, if a data playback command is inputted from the personal computer while the digital television receiver reads the data stored in the AVHDD and plays the read data on the screen, an output signal according to the playback command of the personal computer is provided to the screen of the digital television receiver. In other words, the digital television receiver cannot control the AVHDD, but can only monitor the output signal according to the control of the personal computer.
Accordingly, the digital television receiver is unable to stably receive the desired data from the AVHDD.